Date:         Mon, 2 Nov 1998 08:55:10 -0500
Reply-To:     Michael Sullivan <sullivan@OPENMARKET.COM>
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Michael Sullivan <sullivan@OPENMARKET.COM>
Subject:      Re: Mercedes Wheels
Comments: To: Ari Ollikainen <Ari@OLTECO.com>
Comments: cc: vanagon@vanagon.com
Content-Type: text/enriched; charset="us-ascii"

Dear Ari,


Wheel bearings are engineered for a certain optimal loading "balance" -- this is maintained by offset, which should be proportionately smaller for each increase in width. The math is quite simple, actually. For example, the theoretical offsets for Vanagon rim widths should be:


5.5" rim = ET35 (stock)

6.0" rim = ET31.8

6.5" rim = ET28.6

7.0" rim = ET25.4

7.5" rim = ET22.3

8.0" rim = ET19.1

8.5" rim = ET15.9


In practice, you buy what you can. For example, my 14x7" rims have an offset of ET23, which is close enough. The problem with a 6" Mercedes/Audi rim is that it has an offset of ET43, which is not "close enough" to the engineered optimum in my book (i.e. it is off by 11mm). Summary: ET43 is bad for handling, bad for wheel bearing life.


Cheers,

MJS


At 01:50 PM 10/31/98 -0800, Ari Ollikainen wrote:

>Not a flame...but isn't it true that MORE track would cause bearing

>damage quicker that LESS track? Or does it depend on dynamics as

>far as loading the wheel bearings is concerned. A 9/16" inch

>displacement seems a bit too trivial to worry about, other than

>the more obviousl wheelwell clearance problem...




<bold>Michael J. Sullivan

</bold><italic>Director of Catalog Design

Open Market, Inc.

</italic>

'87 GL Syncro Westfalia

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